1. Field of the Invention
The present invention relates to a plasma display panel, and more particularly, to a plasma display panel including a dielectric wall which covers discharge electrodes arranged along a circumference of a discharge cell, and a method of fabricating the same.
2. Description of the Related Technology
In general, a plasma display panel is a flat panel display device, in which a discharge gas is injected between two substrates to generate a discharge. Phosphor layers are excited by ultraviolet rays generated due to the discharge, to display desired numbers, characters, and images.
Referring to FIG. 1, a conventional plasma display panel 100 includes a front substrate 110, a rear substrate 120 facing the front substrate 110, an X electrode 131 and a Y electrode 134 disposed on an inner surface of the front substrate 110. The panel 100 also includes a front dielectric layer 140 covering the X and Y electrodes 131 and 134, a protective layer 150 coated on the front dielectric layer 140, an address electrode 160 formed on an inner surface of the rear substrate 120. The panel 100 further includes a rear dielectric layer 170 covering the address electrode 160, a barrier rib 180 disposed between the front and rear substrates 110 and 120, and red, green, and blue phosphor layers 190 formed in the barrier rib 180.
The X electrode 131 includes a first transparent electrode line 132, and a first bus electrode line 133 formed on the first transparent electrode line 132. The Y electrode 134 includes a second transparent electrode line 135, and a second bus electrode line 136 formed on the second transparent electrode line 135.
In the plasma display panel 100 including the above structure, an electric signal is applied to the Y electrode 134 and the address electrode 160 to select a discharge cell. Once the discharge cell is selected, an electric signal is alternately applied to the X and Y electrodes 131 and 134 to generate a surface discharge from the inner surface of the front substrate 110 and to generate ultraviolet radiation. Visible light is emitted from the phosphor layers 190 in the selected discharge cell to display a still image or a moving picture.
Once the substrates 110 and 120 and the barrier rib 180 are assembled, a vacuum exhaustion process is performed via i) a hole (not shown) defined in, typically, the rear substrate 120, and ii) a pipe (not shown; typically a glass pipe) connected to the hole, so as to remove impure gas from the interior of the panel 100. The hole and pipe are also used to inject a discharge gas, and the hole is sealed after the gas injection. In the conventional display panel 100, the barrier rib 180 of matrix type defines the discharge cells, and the discharge cells have four closed sides. In addition, there is almost no space between the lower portion of the front substrate 110 and the upper end portion of the barrier rib 180. This “tight fit” structure makes it difficult to remove impure gas from the center portion (directed to the barrier rib 180) of the front substrate 110 where generally a great deal of impure gas exists since no exhaustion path of impure gas is provided in that area during the vacuum exhaustion process.
Therefore, the exhaustion of impure gas cannot be performed sufficiently during the vacuum exhaustion process. Consequently, the impure gas remains in the panel 100, and thus, it shortens the lifetime of the panel 100, and problems such as a permanent residual image and an unstable discharge can be generated.
In addition, the discharge starts from a discharge gap between the X and Y electrodes 131 and 134, and is diffused to the outer portion of the X and Y electrodes 131 and 134. Thus, the discharge is diffused along the plane of the front substrate 110, resulting in poor space usability of the discharge cell.
Since the X electrode 131, Y electrode 134, the front dielectric layer 140, and the protective layer 150 are formed on the inner surface of the front substrate 110, the transmittance of the visible light cannot reach even 60%. Therefore, the brightness is reduced.
In a case where the plasma display panel 100 is driven for a long time, the discharge diffuses toward the phosphor layer 190. Accordingly, the charged particles of the discharge gas, sputtered on the phosphor layer 190 due to the electric field, cause a permanent residual image.
In addition, when the high concentration Xe gas of 10 volume % or more is filled in the discharge cell, ionization and excitation of the electrons cause generation of excitons, and thus, the brightness and the discharge efficiency can increase. However, since the high concentration Xe gas is used, an initial discharge firing voltage becomes high.